Cutting device for paper making machine



April 23, 19 63 v I R. e. MINARIK 3,08 I CUTTING DEVICE FOR PAPER MAKINGMACHINE Filed Dec. 12, 195a 4 Sheets-Sheet 1 April 23, 1963 R. e.MINARIK CUTTING DEVICE FOR PAPER MAKING MACHINE Filed Dec. 12, 1958 4Sheets-Sheet 2 April 23, 1963 R. G. MINARIK 8 CUTTING DEVICE FOR PAPERMAKING MACHINE Filed Dec. 12, 1958 4 Sheets-Sheet a April 23, 1963 R. G.MINARIK 3,035,416

CUTTING DEVICE FOR PAPER MAKING MACHINE Filed D80. 12, 1958 4Sheets-Sheet 4 III United States Patent 3,086,416 CUTTING DEVICE FORPAPER MAKING MACHINE Rudolf G. Minarik, Menasha, Wis., assignor toKimberly- Clark Corporation, Neenah, Wis., a corporation of DelawareFiled Dec. 12, 1958, Ser. No. 780,133 16 Claims. (Cl. 83-345) Thisinvention relates to improvements in high speed rotary cuttersparticularly adapted for the partial or complete transverse severance ofcontinuously moving sheet stock.

A major object of the invention is to provide a high speed rotary cutterwhich insures a very clean cut through a wide range of operating speedsfor the complete or partial severance of lightweight paper or the liketo produce a plurality of individual sheets, or alternately to provideinterrupted transverse cuts therein. The cutter is particularly adaptedfor the high speed production of paper tissue products such as facialtissues, towels, and toilet paper.

A further object is to provide an improved rotary cutter which willsatisfactorily perform in the above manner at an acceptable ambientnoise level.

Another object is to provide an improved multiple blade rotary cutterthe design of which permits easy access to the blades thereof forreadjustment.

A further object is to provide, in a high speed rotary cutter of theanvil roll and blade roll type, an improved anvil roll wherein cutterwear is confined to replaceable portions thereof and the extent ofwearand noise genera-tion is reduced throughout these portions.

Other objects and advantages will become apparent to persons skilled inthe art, as will various modifications thereof without departure fromthe inventive principles as defined in the appended claims.

In the drawings: I

FIGURE 1 is a fragmentary elevational view of a high speed rotary cutterwith the invention incorporated therein,

FIGUREZ is a vertical section taken along line 22 of FIGURE 1,

FIGURE 3 is a vertical section taken along line 3--3 of FIGURE 1 withportions of the structure partially broken away to best illustrate theconstruction,

FIGURE 4 illustrates in vertical section an anvil roll .of alternateconstruction, partly broken away, to best illustrate the constructionaldetails, and

FIGS. 5 and 6 are fragmentary elevational views similar to FIG. 1 andillustrating anvil rolls of alternate construction.

In the paper industry, for example, there has arisen a need for animproved high speed cutter, preferably of the rotary type, which iscapable of cleanly cutting lightweight sheet material such as facialtissue, the cut to be made transversely of the stock to provide eithercomplete severance or a substantial severance with interconnecting bondsremaining between a plurality of sheets so formed. The apparatus asshown and described herein incorporates the inventive principles in amanner, for example, to permit a continuously moving web of a verylightweight, relatively flimsy paper stock, or alternately, a quitedifferent type of sheet stock, rapidly to be processed in the abovemanner while insuring clean and attractive slitting of the stock over awide speed range with an appreciable reduction in the operating noiselevel to a satisfactory value even at high operating speeds. Further,the invention taught herein facilitates start-up of the cutter bysubstantially reducing the required initial torque, thus permittingstart-up with relatively thick stock in the cutter.

ice

As shown in FIG. 1, a rotary cutter incorporating the invention includesa pair of rolls generally designated 10 comprising a knife roll 11 andan anvil roll 12. As shown in FIGS. 1 and 2, sheet stock such as a paperweb 13 is fed from a supply source over a driven roll 12 in the arrowdirection to known apparatus, not shown, for further processing orrewind-ing. Web 13 may, for example, be drawn by rolls 29 and 30 from adriven stock roll which pays out the material at a metered speed withthe web being maintained under slight tension between the meteringapparatus and the anvil roll 12 to insure snug engagement between theweb and the surface of roll 12 as the paper passes over a portion ofthat roll to a rewinder at a speed which may differ from the roll speed.For practical reasons, it is quite desirable that the rate at which Web13 is fed through the cutter be divorced from dependency upon thecircumferential speed of anvil roll 12, since the anvil rollperiodically requires re-surfacing by grinding operations whichprogressively reduce the roll diameter. Under certain conditions the webspeed might be synchronized with the roll speed in which instances roll12 is in effect a feed roll, since there is no relative movement betweenthe web and the roll surface, but this is not its primary purpose, noris the operation of .the cutter in any way dependent upon thatcondition.

Both cutter roll 11 and anvil roll 12 are preferably of solidconstruction, such as being formed from steel forgings or the like, withtheir journal shafts formed integrally of the rolls, it being understoodthat the rolls are suitably journalled in heavy-duty supportingstructure to permit the rolls to withstand relatively large impactforces during the operation of the device while accurately maintainingtheir spaced relationship. Anvil roll 12 is provided with a smoothlyground generally cylindrical surface which minimizes friction betweenthe web and that surface as the web moves over the roll surface underlight tension.

The function of cutter roll 11, which is driven in counter-rotation withrespect to anvil roll 12 and carries one or more knife blades 18, threebeing shown, is successively to move each of the outermost cutter knifeedges 14 into pressure engagement with web 13 along a contact linetransversely of the web at a position within the nip area between rolls11 and 12 and slightly offset from the position of the narrowest nipdimension in a direction counter to roll rotation. At the position ofinitial blade edge contact, that portion of the web to be cut preferablyhas passed beyond the point of initial contact with the roll surface,hence is in contiguous engagement with and thus firmly supported by roll12 along the line of knife edge engagement. The exact positioning of theline of initial knife engagement with the web is of course independentof the roll speeds or the relation of the web speed thereto, and may beselected, within limits, by a desired positioning of the knife which isscribed below.

As shown in FIGS. 2 and 3, knives 18 are symmetrically disposedchordally rather than radially in respect to the circular cross sectionof roll 11, with the three knives shown in angularity. The knife bladesmay be of relatively heavy bar stock of generally slab configuration andof a material such as tool steel which may permit the cutting edge 14 tobe formed directly on the bar, or alternately, the cutting edge may beformed of carboloy or other hard metal suitably fixed to one end of theblade as shown at 19, FIG. 3. T he cutter performs well with knives, theflexible portions of which range in thickof the width of sheet stock tobe cut. The blades may extend substantially the length of roll 11, witheither a continuous edge or a serrated edge as shown in FIG. 1, to leaveinterconnecting bonds in the stock material, with the base of each bladesecurely clamped to the cutter roll in channel-like relieved areasformed therein to position substantial unsupported portions of theblades free of the roll structure, with those portions terminating incutting edges disposed radially outwardly of the cylindrical rollsurface. Alternately, uncut bonds may be left in the stock by providingspaced circumferential grooves or a single spiral groove in the anvilroll to permit use of a knife with a continuous edge. A modified rotarycutter according to the invention is illustrated in FIG. 5, and thiscutter is similar to that illustrated in FIG. 1 but includes an anvilroll 12a having a plurality of such spaced circumferential grooves 12bin its outer surface, and another modified rotary cutter according tothe invention is illustrated in FIG. 6 which includes an anvil roll 120!with such a spiral groove 12e.

FIG. 3 shows in detail a cantilever type knife mounting which has beenfound quite satisfactory for its intended purpose, namely to positivelyanchor the base of the blade to the solid blade roll in a manner topermit the outer blade portion freely to flex under force componentsimparted by contact between the blade and the surface of the anvil roll.Such contact is made in a position to deflect the edged portion of eachblade downwardly as viewed in FIG. 3, or to the left as viewed in FIG. 2during each revolution of roll 11. Each knife mount is disposed in anaxially extending channel of the cross sectional configuration shown.Blade 18 is bored along its inner edge to receive a plurality of clampbolts 20 the shanks of which are of less diameter than the blade boresto permit blade adjustment, with bolts 20 extending through a suitablybored bar clamp 21. As shown, the bolts also project through asupporting shim 24, or the knife blade may rest directly on the roll ifdesired. The bolt ends threadedly engage the roll to provide a strongclamp.

Selective adjustment of blade 18 to position the cutting edge 14 thereofis facilitated by studs 23 which whet} adjusted and locked in place bytheir nuts insure proper positioning of the blade during tightening ofstuds 20. When securely clamped in that position, the free blade portionmay be flexeddownwardly, the chordal platform upon which shim 24 restsbeing relieved beneath the free blade portion as shown to assure freeblade flexure. Alternate types of mountings which position the blade toallow flexure, with the cutting edge outwardly of the roll surface, maybe employed without departure from the invention.

Operation of the cutter shown in FIGS. 1 through 3 is as follows. Withthe rolls 11 and 12 power driven in counter rotation as indicated by thearrows, FIG. 2, and with sheet stock material 13 to be processed movingover roll 12 in the arrow direction of that roll, but not necessarily atroll speed, initial contact between the cutting edge of knife 18 and theouter surface of material 13 will occur approximately at the positionshown in FIG. 2. Assuming first that rolls 11 and 12 are rotating at thesame peripheral speed, and that material 13 is sheet stock such asfacial tissue which is travelling in this instance at roll peripheralspeed, the cutting action is as follows.

Initial contact between knife edge 14 and the web stock 13 occurs alonga line slightly below the position of minimum nip clearance or rollspacing as shown in FIG. 2, as the knife is rotated counter-clockwisetoward the clockwise rotating anvil roll. The free end of knife 18extends outwardly from the knife roll sufficiently that edge 14 thereoftranscribes an are, a minor portion of which intersects a minor portionof the circumferential circle of anvil roll 12. The initial contact ofedge 14 with moving stock 13 is followed by a cutting of the stock asfurther rotation of roll 11 forces the knife edge through the stock andagainst the surface of anvil roll 12. With rolls 11 and 12 traveling atthe same peripheral peed and with no relative movement between stock 13and the surface of the anvil roll, the cut is made with a relativelysmall amount of wiping action occurring between the knife edge and thestock and anvil roll surfaces.

Knife edge 14 is positioned outwardly of roll 11 to an extent that uponseverance of the stock and positive engagement with the anvil rollsurface, edge 14 has not moved into alignment with the narrowest portionof the nip, hence continued rotation of roll 11 results in lateralflexing of the free portion of blade 18 in a direction away from thesurface of anvil roll 12 with a consequent movement of edge 14 to aposition closer to its axis of rotation. With the knife and anvil rollsrapidly rotating concurrently with the flexing of blade 18, the free endof the knife, hence edge 14, is flexed by the rotational forces involvedonly to the extent necessary to permit edge 14 to pass through the nipwhile remaining in firm engagement with the surface of roll 12 until thenip diverges in the machine direction and the knife is eventuallywithdrawn from both the roll and stock as it continues its rotation. Thedeflection of blade 18 is of course just suificient to permit edge 14 toclear the surface of roll 12, and since the applied forces are afunction of the dimensions involved there is little tendency towardrelative movement between the knife edge and the anvil roll surfaceduring passage of the blade through the nip. The knife may be spirallyground if it is desired to employ a progressive cut.

Depending upon the stock material involved and the type of cut desired,wiping action during a cutting operation may or may not be desirable.While the above described cut has been made under conditions whichminimize or eliminate such wiping action, other .operating conditionsmay however be selected to permit such action. 'For example, byoperating rolls 11 and 12 at different circumferential speeds or bymoving stock 13 over roll 12, as by feed rolls 29 and 30 at a speeddifferentfrom the roll speed any desired degree of wiping action may beintroduced, and such action may be caused to occur either counter to orin the direction of stock feed through the cutter. For example, if roll11 is driven at a greater circumferential speed than is roll 12, withstock 13 driven at the speed of roll 12, a wiping action will .occur inthe direction of the stock feed, due to relative movement between theblade edge and anvil roll surface, whereas with roll 11 driven at aslower speed than roll 12 under like circumstances the wiping actionwill be counter to the direction of stock feed.

In the above examples, the stock speed is synchronized with thecircumferential speed of the anvil roll, but as above stated the stockspeed may be controlled independently of the anvil roll speed. When thestock speed is substantially greater than the anvil roll speed, withrolls 11 and 12 rotating at the same circumferential speed, cutting ofthe stock is followed by a slight pulling of the stock material over thetop of roll 12 and away from edge 14 as the edge firmly engages thesurface of the anvil roll during travel through the nip. Such a pullingaction, at least when relatively non-elastic material is being cut, willbe accompanied by a slight slackening of the stock material below theknife, since the stock feed rate is higher than the circumferentialspeed of the anvil roll surface to which it is being applied, andrelative movement between the stock and the anvil roll surface ismomentarily arrested as edge 14 makes the cut and moves through the nip.The type of wiping which takes place differs from that caused by knifeedge movement over the anvil roll surface, since the stock is actuallypulled outwardly of the blade. Wiping from the opposite side of theblade edge will result when the anvil roll speed exceeds the stock rateof speed, and under other conditions the movement of the stock inrespect to the blade results in '5 a somewhat different type of actionwhich resembles in effect a wiping action.

The cutter is thus adapted to a wide range of flexibility in respect tothe control of the type of cut to be made, through selection of desiredrelationships between anvil roll speed, stock feed speed, and cutterspeed, and as is further evident the type of cut may also be controlledthrough the adjustment of knife 18 since it is the positioning of thecutting edge 14 thereof which controls the magnitude of intereferencebetween that edge and the surface of the anvil roll, hence thedeflection thereof, as the knife edge passes through the nip. It isfurther apparent that any suitable number of knives 18 may be employedso long as the cutting edges thereof are positioned to transcribe acommon circumferential path. The knives need not necessarily be mountedon a generally cylindrical roll, such as shown at 11, it being merelynecessary to suitably fix the knives to a rotatable member in a mannerto permit free portions thereof which terminate in the knife edges to beflexed in the manner above described upon contact with the stock and theanvil roll surface.

As shown in FIG. 4, anvil roll 12a is modified in a manner to provide aplurality of cantilever mounted inserts 26 providing bed plates with theouter surfaces 26a thereof in circumferential registry with the rollsurface. The inserts are recessed in axially extending channels whichform mounting shoulders as shown to which base portions of the bedplates are securely clamped by bolts 27 to position the non-supportedportions laterally of the shoulders. FIG. 4 illustrates an anvil roll asviewed for counter-clockwise rotation, it being understood that ifmounted as shown in FIG. 2 the free portion would trail the clampedportion during clockwise rotation. With the anvil roll 12a switched endfor end and substituted for 12 in the structure of FIG. 2, operation isas follows. Bed plates 26, corresponding in number to knives 18, arecircumferentially spaced for registry therewith, blade edges 14preferably engaging the free or unsupported portions of the bed platenear the trailing edge thereof. As rotational forces are progressivelyapplied by a knife 18, as it starts a cut, to the trailing surface of abed plate, the free portion of the plate is flexed inwardly when thoseforces become of a sufficiently high order simultaneously to also causethe knife to flex in a counter direction. Since the effective radii ofboth the anvil and knife rolls is simultaneously reduced by the enlargedmembers, both of which yield, no relative movement, hence no wipingaction, occurs therebetween. The above described combination of aflexible knife and a yieldable bed plate re sults in a reduction in bothknife edge wear and operating noise level and may be employed with thevarious stock and roll speed combinations above described to alter thenature of the cut as desired.

With the cutter operating in a manner completely to sever the sheetstock, that portion of the stock, held under tension from the feed roll,after severance from that portion of the stock passing over the top ofthe anvil roll, must of course be momentarily held in contiguousengagement with the surface of the anvil roll by a bond capable ofcounteracting the stock tension which would otherwise pull the stockclear of the roll surface. It has been found that at least when fibrousmaterials such as tissue paper, light webbing, and other paper stock areprocessed through the cutter, the knife action during each cutadequately serves to adhere the stock marginally of the cut sulficientlyto resist the tangentially applied forces of tension, hence the feedstock from which a portion has been cut moves over the top of the anvilroll preparatory to a subsequent cut. FIG. 2 shows only the manner inwhich interconnected stock is taken off the anvil roll. The removal ofseparate sheets may be done in a known manner which forms no part ofthis invention.

I claim:

1. In a rotary cutter, :a rotatably mounted member, an inherentlyflexible knife mounted on said member for rotation about an axis withthe major plane of the knife disposed chordally of a circle transcribedabout said axis, and an anvil roll mounted for rotation about an axis inparallel spaced relation to the axis of kmfe rotation and having a hardsurface on its periphery, said knife having a cutting edge positionedradially of its axis of rotation at a distance to transcribe a path, aminor portion of which intersects a minor portion of the circumferentialpath of said anvil roll, with the knife cutting edge having a clearancewith said member and being freely movable toward said axis against theflexing action of the knife, and means driving said member and anvilroll in counter rotation so that said cutting edge strikes said hardanvil surface and flexes to have a cutting action with the anvil roll.

2. In a notary cutter, a knife roll, a hard surfaced anvil roll, meansrotatably mounting said rolls in parallel spaced relation to form anopen nip therebetween, means driving said rolls in counter rotation, asubstantially flat inherently flexible knife having a base fixed to saidknife roll and a non-supported portion disposed chordally of the rolland having a clearance with the roll and terminating in .a cutting edgepositioned outwardly of the circumferential surface thereof and slightlybeyond the minimum transverse nip dimension so that the knife flexestoward the roll when the cutting edge contacts said anvil roll to have acutting action therewith, and means for feeding sheet stock through saidnip and over said anvil roll for severance by said knife when rotatedinto said nip and into contacting engagement with said anvil roll.

3. In a rotary cutter, a rotatably mounted anvil roll having a hardsurface on its periphery, a rotatable member in parallel spaced relationthereto, means driving said roll and member in counter rotation, aninherently flexible knife and means fixing said knife to said memherwith an unsupported portion of the knife extending chordally withrespect to a circle about the axis of said member and having a clearancewith the member and terminating in a cutting edge extendingsubstantially parallel to the surface of the anvil roll and positionedradially of the axis of member rotation to prevent clear- .ance pastsaid hard surface of the anvil roll upon rotation of said member,whereby rotation of said member causes said cutting edge to engage theanvil roll and to be deflected thereby sufficiently toward the axis ofmember rotation against the inherent flexibility of said knife to allowthe knife to pass through the nip of the knife and anvil roll, and meansfor passing sheet stock over said anvil roll to be cut by said edge asit rotates into engagement with said anvil roll.

4. The device of claim 3 wherein said knife edge is provided with aninterrupted edge. 7

5. The device of claim 3 wherein said anvil roll is provided withaxially spaced circumferential grooves.

6. The device of claim -3 wherein said anvil roll is provided withhelical grooves.

7. The device of claim 3 wherein said knife is pro vided with a spirallyground cutting edge.

8. The device of claim 3 wherein said knife is provided with adiscontinuous edge and means are provided for continuously feeding sheetstock through the nip of said knife :and anvil roll while engaging thenip of said knife and anvil roll while engaging the nip defining surfaceof the anvil roll for the interrupted transverse cutting of said stock.

9. The device of claim 3 wherein said roll and member are driven at suchspeeds that said knife edge has a greater speed than said anvil roll atits peripheral surface.

10. The device of claim 3 wherein said roll and memher are driven atsuch speeds that said knife edge has a slower speed than said anvil rollat its peripheral surface.

11. In a rotary cutter, a knife roll, an anvil roll provided with aninherently flexible bed plate mounted on the anvil roll as a cantileverwith an unsupported portion so as to extend substantiallycir-cumferentially thereon with a clearance being provided between theunsupported portion of the bed plate and the anvil roll to permitflexing of the unsupported bed plate portion toward the anvil roll,means for rotatably mounting said rolls in parallel spaced relation toform an open nip therebetween, a knife fixed to said knife roll andterminating in a cutting edge positioned outwardly of the knife roll ata distance slightly beyond said nip, and means for driving said rolls incounter rotation with said cutting edge positioned for contactingengagement with the unsupported portion of said bed plate so that stockfed through said nip is severed by said knife when rotated into said nipto contact said bed plate and flex the bed plate against its inherentresiliency.

12. In a rotary cutter, a rotatably mounted member a flat inherentlyflexible knife mounted on said member for rotation about an axis withthe plane of the knife disposed chordally of a circle transcribed aboutsaid axis, and an anvil roll mounted for rotation about an axis inparallel spaced relation to the axis of knife rotation and having a hardsurface on its periphery, said knife being mounted as a cantilever witha major portion of its length terminating in its cutting edge beingunsupported and having a clearance with said member and being arrangedto be free to move toward said axis with flexing of the knife with thecutting edge positioned radially of its axis of rotation at a distanceto transcribe a path, .a minor portion of which intersects a minorportion of the circumferential path of said anvil roll, and meansdriving said member and anvil roll in counter rotation so that saidcutting edge strikes said hard anvil surface and flexes to have acutting action with the anvil roll.

13. A rotary cutter having in combination, a knife roll, a hard facedanvil roll, means mounting said rolls to form an open nip therebetween,means driving said rolls in opposite directions, a plurality ofsubstantially flat inherently flexible knife blades mounted ascantilevers on said knife roll with unsupported portions thereof havingclearances with the knife roll and terminating in cutting edgespositioned outwardly of the knife roll surface for contacting engagementwith the surface of the anvil roll, the normal circular path transcribedby said knife ledges intersecting a minor circumferential portion ofsaid anvil roll adjacent the area of blade contact therewith, wherebycontact between the cutting edges and anvil roll surface causes saidblades to be flexed in a direction toward said knife roll to move theedges inwardly of said .normal path to permit blade movement past theanvil roll and provide blade cutting action with said anvil roll.

14. In a rotary cutter, 'a knife roll, an anvil roll provided with a bedplate mounted thereto as a cantilever with an unsupported portion so asto extend substantially circumferentially thereof with the unsupportedportion of the bed plate having a clearance with the anvil roll, meansfor rotatably mounting said rolls in parallel spaced relation to form anopen nip therebetween, an inherently flexible knife having a baseportion fixed to said knife roll and a non-supported portion terminatingin a cutting edge positioned outwardly of said roll at a distanceslightly beyond said nip with the non-supported portion having aclearance with respect to said knife roll, means for driving said rollsin counter rotation with said cutting edge positioned for contactingengagement with the free portion of said bed plate whereby said knifeflexes towards said knife roll and said bed plate flexes toward saidanvil roll, and means for feeding sheet stock through said nip and oversaid anvil roll for severance by said knife when rotated into said nipto contact said bed plate.

15. In a cutter, a rotatably mounted generally cylindrical anvilprovided with a plurality of inherently flexible bed plates each ofwhich is mounted as a cantilever on the anvil with an unsupportedportion so as to extend substantially circumferentially thereof and withthe unsupported part of each bed plate having a clearance with respectto the anvil, a knife roll in parallel spaced relation to said anvil, aplurality of inherently flexible knives extending chordally with respectto the axis of the knife roll and having base portions thereof fixed tothe knife roll and substantially free portions terminating in cuttingedges disposed parallel to the anvil roll taxis and outwardly of theknife roll to transcribe a circular path, a minor portion of whichintersects with the circumferential path of the anvil, with saidsubstantially free portions of said knives having clearances withrespect to the knife roll, and means for rotating said anvil in onedirection and said knife roll in the opposite direction for pressurecontacting engagement between said cutting edges and bed plates withresulting deflection of said knives towards said knife roll and said bedplates toward said anvil to provide a severing action between saidknives and said bed plates.

16. In a device of the character described, first and second counterrotating rolls in parallel spaced relation to form an open niptherebetween, means for continuously feeding sheet material over saidfirst roll, a substantially rigid but inherently flexible knife fixed tothe second roll as a cantilever with an unsupported portion to extendchordally with respect to the axis of the second roll and with theunsupported portion of the flexible knife having a clearance with thesecond roll to permit flexing of the unsupported portion of the knife,the flexible knife terminating in a cutting edge positioned radially ofsaid second roll slightly beyond the minimum transverse nip dimension,whereby counter rotation of said rolls causes engagement between the:anvil roll and cutting edge and causes said knife to be flexed towardits supporting roll to permit movement of said knife through said nip.

References Cited in the file of this patent UNITED STATES PATENTS1,730,449 Campbell Oct. 8, 1929 2,768,690 Roberts Oct. 30, 19562,870,840 Kwitek Jan. 27, 1959 3,056,323 Kwitek Oct. 2, 1962

14. IN A ROTARY CUTTER, A KNIFE ROLL, AN ANVIL ROLL PROVIDED WITH A BEDPLATE MOUNTED THERETO AS A CANTILEVER WITH AN UNSUPPORTED PORTION SO ASTO EXTEND SUBSTANTIALLY CIRCUMFERENTIALLY THEREOF WITH THE UNSUPPORTEDPORTION OF THE BED PLATE HAVING A CLEARANCE WITH THE ANVIL ROLL, MEANSFOR ROTATABLY MOUNTING SAID ROLLS IN PARALLEL SPACED RELATION TO FORM ANOPEN NIP THEREBETWEEN, AN INHERENTLY FLEXIBLE KNIFE HAVING A BASEPORTION TERMINATING IN A CUTTING EDGE POSITIONED OUTWARDLY OF SAID ROLLAT A DISTANCE SLIGHTLY BEYOND SAID NIP WITH THE NON-SUPPORTED PORTIONHAVING A CLEARANCE WITH RESPECT TO SAID KNIFE ROLL, MEANS FOR DRIVINGSAID ROLLS IN COUNTER ROTATION WITH SAID CUTTING EDGE POSITIONED FORCONTACTING ENGAGEMENT WITH THE FREE PORTION OF SAID BED PLATE WHEREBYSAID KNIFE FLEXES TOWARDS SAID KNIFE ROLL AND SAID BED PLATE FLEXESTOWARD SAID ANVIL ROLL, AND MEANS FOR FEEDING SHEET STOCK THROUGH SAIDNIP AND OVER SAID ANVIL ROLL FOR SEVERANCE BY SAID KNIFE WHEN ROTATEDINTO SAID NIP TO CONTACT SAID BED PLATE.